<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{% block title %} 默认标题{%endblock%}</title>
</head>
<body>
<ul>
    <li><a href="#">首页</a></li>
    <li><a href="#">联系</a></li>
</ul>
{% block body %}
默认内容<br>
{% endblock %}
{% block footer%}
<p>我是尾页</p>
{% endblock %}
</body>
</html>